libgcc/libgcov-interface.c

   1 /* Routines required for instrumenting a program.  */
   2 /* Compile this one with gcc.  */
   3 /* Copyright (C) 1989-2021 Free Software Foundation, Inc.
   4
   5 This file is part of GCC.
   6
   7 GCC is free software; you can redistribute it and/or modify it under
   8 the terms of the GNU General Public License as published by the Free
   9 Software Foundation; either version 3, or (at your option) any later
  10 version.
  11
  12 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
  13 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  14 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  15 for more details.
  16
  17 Under Section 7 of GPL version 3, you are granted additional
  18 permissions described in the GCC Runtime Library Exception, version
  19 3.1, as published by the Free Software Foundation.
  20
  21 You should have received a copy of the GNU General Public License and
  22 a copy of the GCC Runtime Library Exception along with this program;
  23 see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
  24 <http://www.gnu.org/licenses/>.  */
  25
  26 #include "libgcov.h"
  27 #include "gthr.h"
  28
  29 #if defined(inhibit_libc)
  30
  31 #ifdef L_gcov_reset
  32 void __gcov_reset (void) {}
  33 #endif
  34
  35 #ifdef L_gcov_dump
  36 void __gcov_dump (void) {}
  37 #endif
  38
  39 #else
  40
  41 extern __gthread_mutex_t __gcov_mx ATTRIBUTE_HIDDEN;
  42
  43 #ifdef L_gcov_lock_unlock
  44 #ifdef __GTHREAD_MUTEX_INIT
  45 __gthread_mutex_t __gcov_mx = __GTHREAD_MUTEX_INIT;
  46 #define init_mx_once()
  47 #else
  48 __gthread_mutex_t __gcov_mx;
  49
  50 static void
  51 init_mx (void)
  52 {
  53   __GTHREAD_MUTEX_INIT_FUNCTION (&__gcov_mx);
  54 }
  55
  56 static void
  57 init_mx_once (void)
  58 {
  59   static __gthread_once_t once = __GTHREAD_ONCE_INIT;
  60   __gthread_once (&once, init_mx);
  61 }
  62 #endif
  63
  64 /* Lock critical section for __gcov_dump and __gcov_reset functions.  */
  65
  66 void
  67 __gcov_lock (void)
  68 {
  69   init_mx_once ();
  70   __gthread_mutex_lock (&__gcov_mx);
  71 }
  72
  73 /* Unlock critical section for __gcov_dump and __gcov_reset functions.  */
  74
  75 void
  76 __gcov_unlock (void)
  77 {
  78   __gthread_mutex_unlock (&__gcov_mx);
  79 }
  80 #endif
  81
  82 #ifdef L_gcov_reset
  83
  84 /* Reset all counters to zero.  */
  85
  86 static void
  87 gcov_clear (const struct gcov_info *list)
  88 {
  89   const struct gcov_info *gi_ptr;
  90
  91   for (gi_ptr = list; gi_ptr; gi_ptr = gi_ptr->next)
  92     {
  93       unsigned f_ix;
  94
  95       for (f_ix = 0; f_ix < gi_ptr->n_functions; f_ix++)
  96         {
  97           unsigned t_ix;
  98           const struct gcov_fn_info *gfi_ptr = gi_ptr->functions[f_ix];
  99
 100           if (!gfi_ptr || gfi_ptr->key != gi_ptr)
 101             continue;
 102           const struct gcov_ctr_info *ci_ptr = gfi_ptr->ctrs;
 103           for (t_ix = 0; t_ix != GCOV_COUNTERS; t_ix++)
 104             {
 105               if (!gi_ptr->merge[t_ix])
 106                 continue;
 107
 108               memset (ci_ptr->values, 0, sizeof (gcov_type) * ci_ptr->num);
 109               ci_ptr++;
 110             }
 111         }
 112     }
 113 }
 114
 115 /* Function that can be called from application to reset counters to zero,
 116    in order to collect profile in region of interest.  */
 117
 118 void
 119 __gcov_reset_int (void)
 120 {
 121   struct gcov_root *root;
 122
 123   /* If we're compatible with the master, iterate over everything,
 124      otherise just do us.  */
 125   for (root = __gcov_master.version == GCOV_VERSION
 126          ? __gcov_master.root : &__gcov_root; root; root = root->next)
 127     {
 128       gcov_clear (root->list);
 129       root->dumped = 0;
 130     }
 131 }
 132
 133 /* Exported function __gcov_reset.  */
 134
 135 void
 136 __gcov_reset (void)
 137 {
 138   __gcov_lock ();
 139
 140   __gcov_reset_int ();
 141
 142   __gcov_unlock ();
 143 }
 144
 145 #endif /* L_gcov_reset */
 146
 147 #ifdef L_gcov_dump
 148 /* Function that can be called from application to write profile collected
 149    so far, in order to collect profile in region of interest.  */
 150
 151 void
 152 __gcov_dump_int (void)
 153 {
 154   struct gcov_root *root;
 155
 156   /* If we're compatible with the master, iterate over everything,
 157      otherise just do us.  */
 158   for (root = __gcov_master.version == GCOV_VERSION
 159          ? __gcov_master.root : &__gcov_root; root; root = root->next)
 160     __gcov_dump_one (root);
 161 }
 162
 163 /* Exported function __gcov_dump.  */
 164
 165 void
 166 __gcov_dump (void)
 167 {
 168   __gcov_lock ();
 169
 170   __gcov_dump_int ();
 171
 172   __gcov_unlock ();
 173 }
 174
 175 #endif /* L_gcov_dump */
 176
 177 #ifdef L_gcov_fork
 178 /* A wrapper for the fork function.  We reset counters in the child
 179    so that they are not counted twice.  */
 180
 181 pid_t
 182 __gcov_fork (void)
 183 {
 184   pid_t pid;
 185   pid = fork ();
 186   if (pid == 0)
 187     {
 188       __GTHREAD_MUTEX_INIT_FUNCTION (&__gcov_mx);
 189       /* We do not need locking as we are the only thread in the child.  */
 190       __gcov_reset_int ();
 191     }
 192   return pid;
 193 }
 194 #endif
 195
 196 #ifdef L_gcov_execl
 197 /* A wrapper for the execl function.  Flushes the accumulated
 198    profiling data, so that they are not lost.  */
 199
 200 int
 201 __gcov_execl (const char *path, char *arg, ...)
 202 {
 203   va_list ap, aq;
 204   unsigned i, length;
 205   char **args;
 206
 207   /* Dump counters only, they will be lost after exec.  */
 208   __gcov_dump ();
 209
 210   va_start (ap, arg);
 211   va_copy (aq, ap);
 212
 213   length = 2;
 214   while (va_arg (ap, char *))
 215     length++;
 216   va_end (ap);
 217
 218   args = (char **) alloca (length * sizeof (void *));
 219   args[0] = arg;
 220   for (i = 1; i < length; i++)
 221     args[i] = va_arg (aq, char *);
 222   va_end (aq);
 223
 224   int ret = execv (path, args);
 225   /* We reach this code only when execv fails, reset counter then here.  */
 226   __gcov_reset ();
 227   return ret;
 228 }
 229 #endif
 230
 231 #ifdef L_gcov_execlp
 232 /* A wrapper for the execlp function.  Flushes the accumulated
 233    profiling data, so that they are not lost.  */
 234
 235 int
 236 __gcov_execlp (const char *path, char *arg, ...)
 237 {
 238   va_list ap, aq;
 239   unsigned i, length;
 240   char **args;
 241
 242   /* Dump counters only, they will be lost after exec.  */
 243   __gcov_dump ();
 244
 245   va_start (ap, arg);
 246   va_copy (aq, ap);
 247
 248   length = 2;
 249   while (va_arg (ap, char *))
 250     length++;
 251   va_end (ap);
 252
 253   args = (char **) alloca (length * sizeof (void *));
 254   args[0] = arg;
 255   for (i = 1; i < length; i++)
 256     args[i] = va_arg (aq, char *);
 257   va_end (aq);
 258
 259   int ret = execvp (path, args);
 260   /* We reach this code only when execv fails, reset counter then here.  */
 261   __gcov_reset ();
 262   return ret;
 263 }
 264 #endif
 265
 266 #ifdef L_gcov_execle
 267 /* A wrapper for the execle function.  Flushes the accumulated
 268    profiling data, so that they are not lost.  */
 269
 270 int
 271 __gcov_execle (const char *path, char *arg, ...)
 272 {
 273   va_list ap, aq;
 274   unsigned i, length;
 275   char **args;
 276   char **envp;
 277
 278   /* Dump counters only, they will be lost after exec.  */
 279   __gcov_dump ();
 280
 281   va_start (ap, arg);
 282   va_copy (aq, ap);
 283
 284   length = 2;
 285   while (va_arg (ap, char *))
 286     length++;
 287   va_end (ap);
 288
 289   args = (char **) alloca (length * sizeof (void *));
 290   args[0] = arg;
 291   for (i = 1; i < length; i++)
 292     args[i] = va_arg (aq, char *);
 293   envp = va_arg (aq, char **);
 294   va_end (aq);
 295
 296   int ret = execve (path, args, envp);
 297   /* We reach this code only when execv fails, reset counter then here.  */
 298   __gcov_reset ();
 299   return ret;
 300 }
 301 #endif
 302
 303 #ifdef L_gcov_execv
 304 /* A wrapper for the execv function.  Flushes the accumulated
 305    profiling data, so that they are not lost.  */
 306
 307 int
 308 __gcov_execv (const char *path, char *const argv[])
 309 {
 310   /* Dump counters only, they will be lost after exec.  */
 311   __gcov_dump ();
 312   int ret = execv (path, argv);
 313   /* We reach this code only when execv fails, reset counter then here.  */
 314   __gcov_reset ();
 315   return ret;
 316 }
 317 #endif
 318
 319 #ifdef L_gcov_execvp
 320 /* A wrapper for the execvp function.  Flushes the accumulated
 321    profiling data, so that they are not lost.  */
 322
 323 int
 324 __gcov_execvp (const char *path, char *const argv[])
 325 {
 326   /* Dump counters only, they will be lost after exec.  */
 327   __gcov_dump ();
 328   int ret = execvp (path, argv);
 329   /* We reach this code only when execv fails, reset counter then here.  */
 330   __gcov_reset ();
 331   return ret;
 332 }
 333 #endif
 334
 335 #ifdef L_gcov_execve
 336 /* A wrapper for the execve function.  Flushes the accumulated
 337    profiling data, so that they are not lost.  */
 338
 339 int
 340 __gcov_execve (const char *path, char *const argv[], char *const envp[])
 341 {
 342   /* Dump counters only, they will be lost after exec.  */
 343   __gcov_dump ();
 344   int ret = execve (path, argv, envp);
 345   /* We reach this code only when execv fails, reset counter then here.  */
 346   __gcov_reset ();
 347   return ret;
 348 }
 349 #endif
 350 #endif /* inhibit_libc */